Access pump through IP address

Hi all
Having trouble accessing my new water pump through its IP address.
It's a Royal Exclusive RD4 500w, from Germany which can be seen on their website with instructions.
Unfortunately there are no controls on the pump, so the only way I can change the speed is by way of connecting it to the router.
I have a BT home hub, and I've been told the range isn't big enough, and the 3rd number of the routers IP address needs to see a 0, same as the pump.
I've tried to change the IP address of the router range and it just keeps coming up with invalid IP number.
Any help would be appreciated
Many thanks
Dave

HI mate
Thank you for your reply I really appreciate.
I've had another play this evening, if I plug the pump straight into the laptop, and turn the Wi-Fi off as you requested, the laptop recognises something is lugged in, but nothing pops settings pop up at all.
Surely for me to get to that stage in the instructions it needs to be accessed through the internet via my router?

Ok, so did 192.168.0.245 in default gateway as I think you requested, I didn't lose internet connection.
Googled SRC and all sorts came up, not sure what to look for. Don't suppose you live near Hastings?